The days when people could interact with friends who are distant only through phone calls are gone. The days when people wrote diaries or letters to friends are also gone. Instead, people in today’s world use Social Networking System, shortly SNS, to communicate with others. As more and more people have started to depend on SNS for communication, it has changed people’s daily lives in many different ways, both in a good and a bad way. Today, I want to talk about the effects of SNS on people’s daily life, especially on human relationships people form in society: SNS both broadens and shallows human relationships.On one hand, SNS has broadened human relationships among people. This could have been possible since SNS allows people to get to know others without seeing them in person. Thus, SNS has no territorial boundaries and requires much less burden and time for making friends. Such characteristics of SNS have made people communicate with various people including someone who is far away or whom they have never met in real life. Truly, people can form much more human relationships with less effort and time through SNS. In this way, people can broaden their human relationships through SNS, which enables people to make more friends than in real world. This proves that SNS has become an easier and faster way to interact with people without time or territorial boundaries, which consequently helps broadening human relationships.On the other hand, SNS has also made human relationships less deeper, because SNS lets people communicate through uploading pictures and writing posts online, people meet in person less necessary than the past when meeting up was the most common way to communicate.Then there is less opportunity for people to have deep conversations with friends, because the depth of conversation is quite limited when people talk on SNS, which blocks eye contact and etc. Additionally, even when people meet each other in real life, most of them tend to look at their cell phones a lot to see their SNS. There is even a word for people who are addicted to SNS, and such reality reveals how people are obssessed with SNS for human interacting. This shows how the characteristics of SNS that helped broadening human relationships also make them less deeper. Technological advances have made people’s lives much more fruitful, and SNS is definitely one of them. However, people should always be aware of that it brings both positive and negative effects; SNS broadens and shallows human relationships at the same time. Thanks to its characteristics of easier and faster interaction, people can make more new friends at any time and at any place, but also because of them, there are fewer chances for people to have deep and trustful talk with others. It is important that people acknowledge both positive and negative effects of SNS so that they can balance the life on SNS and the life in real world. When people succeed in the balancing, they will have more friends whom they can trust, truly love and communicate at any time and at any place.